Although your enemy are only armed with pistols, and the police with shotguns, the sheer weight of numbers of both of these groups make it pretty near impossible to complete this mission without miniguns just so you don't run out of ammo!

Get in the car, and head out of the gates. As soon as you hit the gates try and head south, even though you can't see anything outside the gates due to a building being in the way - in my experience even if you try and head east the car will decide to go south anyway! As soon as you can see the car emerge from underneath the building jump out, as there is an enemy agent very close by.

Go into panic mode and head south, taking out all opposing forces as you go - there'll only be about four enemy agents. Then when you reach the bottom of the mission area head east, you'll pass under the railway line, go past the building you mission target is in, under a walkway, and finally past a building to the far south-eastern corner wherethere's a ramp up to the walkways. When you've cleared the local area of enemy agents get on the ramp and head west, back the way you came and towards the railway line. Head south as soon as you can, following the scanner to the mission target.

Split your agents in two; get one of them to walk part way up the ramp to the railway platform, where he has a good view of the street; the other agent, the one with the persuadertron, should keep heading towards the target. More enemy agents should stream down from the north, but the agent on the walkway to the railway platform will hold them off - if you have level one upgrades for heart, eyes and brain he'll probably start to become immune to the drugs, so keep an eye on him as you send the other agent to <persuade> the target (there are no guards, so there's no need to guide the <persuading> agent much).

Once the lookout has taken out all the enemy agents, take both agents down to minimal drug usage so that they don't outrun their convert. Go back the way you came, not forgetting to pick up the car on the way so that you can get back through the gates.

It's almost possible to do this level with one agent and one minigun if you're up for a challenge - you'll run out of ammo so steal a few shotguns off the police.

If you do use two agents, it might be best to get the one without the persuadertron to run and get the car, as it's quicker than walking at the same speed as the kidnap victim all the time.